The principle for three-dimensional stereoscopic display technology is that left and right eyes receive a pair of images with parallax at the same time so as to form 3D effect by a processing using the human's brain.
The three-dimensional stereoscopic display is mainly classified into a naked eye type and a glasses type. The naked eye type stereoscopic display technology is mainly classified into a parallax barrier type and a lenticular lens type. For a liquid crystal parallax barrier, its implementation method is to produce a series of alternate light-shielding and light-transmitting stripes with a liquid crystal layer and a polarizer to form a liquid crystal grating for splitting light. With the liquid crystal parallax barrier, in a stereoscopic display mode, when a left eye image to be seen by the left eye is displayed on a display panel, the light-shielding stripes may make the left eye image not be seen by the right eye. Similarly, when a right eye image to be seen by the right eye is displayed on the display panel, the light-shielding stripes will make the right eye image not be seen by the left eye. By separating the left eye image and the right eye image, it is possible to make the viewer have a stereoscopic vision. The liquid crystal parallax barrier may be compatible with a conventional manufacturing process of a liquid crystal display panel, therefore it has advantages in terms of mass production and cost.
At present, a product with a combination of a 3D display function and a touch function attracts more and more attentions. However, at present, a structure of a touch screen plus a liquid crystal grating as shown in FIG. 1 is usually used, the structure of the touch screen plus the liquid crystal grating includes a first electrode layer 11, a second electrode layer 12 and a touch electrode layer 13, wherein the touch electrode layer includes a second touch electrode layer and a first touch electrode layer, that is, the structure has at least four layers of electrodes. Moreover, more electrode layers will decrease light transmittance of the entire liquid crystal grating and influence the display effect. Since both substrates have electrodes disposed thereon, a conductive adhesive is needed to transmit a voltage signal and it is also required to dispose alignment marks on the two substrates respectively for precise cell-assembling, which increases the complexity degree of manufacturing and the manufacturing cost. In addition, the structure of the touch screen plus the liquid crystal grating has a large thickness, which will certainly influence the transmittance and display effect of the entire 3D display device.